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      This patch makes it possible to do region assignment without ZK. By default, it is off (i.e. ZK is used for region assignment as before).

      Two setting "hbase.assignment.usezk", "hbase.assignment.usezk.migrating" are introduced to control migration from using ZK for assignment to not using
      ZK for assignment.

      For rolling upgrade from using ZK to not using ZK, it can be done in two steps:

      1. Set both hbase.assignment.usezk and hbase.assignment.usezk.migrating to true, do a rolling upgrade so that both masters and regionservers have
      the new code. Either master or regionserver can be upgraded at first. The order is not important for this step. If you want to keep using ZK for assignment, you'd better set hbase.assignment.usezk to true, and hbase.assignment.usezk.migrating to false so that region states are not persisted in meta table.

      2. Set hbase.assignment.usezk to false, do a rolling restart so that region assignments don't use ZK any more. For this step, masters should be restarted after regionservers have all restarted at first so that they won't update meta table directly and master doesn't know about it.
      Show
      This patch makes it possible to do region assignment without ZK. By default, it is off (i.e. ZK is used for region assignment as before). Two setting "hbase.assignment.usezk", "hbase.assignment.usezk.migrating" are introduced to control migration from using ZK for assignment to not using ZK for assignment. For rolling upgrade from using ZK to not using ZK, it can be done in two steps: 1. Set both hbase.assignment.usezk and hbase.assignment.usezk.migrating to true, do a rolling upgrade so that both masters and regionservers have the new code. Either master or regionserver can be upgraded at first. The order is not important for this step. If you want to keep using ZK for assignment, you'd better set hbase.assignment.usezk to true, and hbase.assignment.usezk.migrating to false so that region states are not persisted in meta table. 2. Set hbase.assignment.usezk to false, do a rolling restart so that region assignments don't use ZK any more. For this step, masters should be restarted after regionservers have all restarted at first so that they won't update meta table directly and master doesn't know about it.

      Description

      It seems that most people don't like region assignment with ZK (HBASE-5487), which causes many uncertainties. This jira is to support ZK-less region assignment. We need to make sure this patch doesn't break backward compatibility/rolling upgrade.

        Attachments

        1. hbase-11059_v2.1.patch
          286 kB
          Jimmy Xiang
        2. hbase-11059_v2.2.patch
          296 kB
          Jimmy Xiang
        3. hbase-11059_v2.patch
          261 kB
          Jimmy Xiang
        4. hbase-11059_v3.0.patch
          309 kB
          Jimmy Xiang
        5. hbase-11059.patch
          289 kB
          Jimmy Xiang
        6. zk-less_am.pdf
          119 kB
          Jimmy Xiang
        7. zk-less_assignment.png
          20 kB
          Jimmy Xiang

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              • Assignee:
                jxiang Jimmy Xiang
                Reporter:
                jxiang Jimmy Xiang
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